Alright.
Time for an update. Apologies for wall of text. I normally over-illustrate my posts, but this one will be an exception!
Been thinking about the next step for the wedge and more specifically the 2zz for a while. What I plan to do is address some of the weaknesses of the 2zz, and make it a bit more fun to drive = more power. It is already a hoot to drive especially up in the revs, but you can never make too much power right? Especially if there is more power under the curve across the whole RPM range!
This is not going to be an all out NA or turbo build - sure it’s only my weekend warrior car at the moment, but it needs to be able to assume daily driving duties should the need arise. Track days are a must too.
Never ideal building a car and motor suit two different applications as this means compromises somewhere along the way, but hey that’s just the way it goes sometimes.
Engine wise, this means trying to get a bit more power and torque down low as well as reinforcing its natural tendency for peaky power.
Well documented weaknesses of the 2zz and limitations for my current (and future!) power aspirations tend to be:
- Oil pump
- Oil ban and baffling
- Valves
- Valve springs
- Intake manifold
Oil pump - The 2zzge is known to explode an oil pump with a money shift. The oil pump is sintered iron, so is brittle and not as strong as it could have been stock. Toyota, why you make an ‘economy’ piece on a performance engine?? There are CNC milled replacement units available either as just the gear set or a replacement pre-assembled oil pump with the stronger gears.
Oil pan and baffling - I have addressed this with the BOE oil pan I installed a year back, and is still one of the best if not the best oil pan for a 2zz without dropping 5k on a dry sump setup. Nice touch of the BOE aluminium pan over a Moreoso is the BOE can be left in place when dropping the motor – it can take the combined weight of engine and gearbox where the Moreoso aluminium sump you need to remove to save squashing it.
I will add a thermostatic (80 degrees opening) thermostatic oil sandwich plate and finally get around to installing the 9 row oil cooler that's sat unloved on a garage shelf now for years. With only a 9 row cooler and positioning this in the engine bay isn't going to net the best cooling possible, but it’s a beginning step I can always come back to and re-design and stick the cooler somewhere else or get a bigger one if it's not cutting it. I haven't seen temperatures over about 130 degrees on track yet, but even if this was 15 degrees less it will help with oil longevity and efficiency.
Valves and springs - It is known the stock springs and valves are weak points, and aren't up to the task of sustained high RPM, and it's not a good idea to drop in a set of aftermarket cams with stock springs due to coil bind. Replacing these with some 15% stiffer springs and stainless valves will remedy this and allow revving out to 9k+ which while isn't my primary focus it's definitely a bonus. Will be interesting with the stock tacho running out at 9k though, lets hope the tacho and speedo needles never meet each other in the middle….
An upgrade to the valvetrain will allow a drop in set of cams too which will give some more “hoorah” to this NA motor. A set of stainless flat faced valves instead of the recessed factory valves will see a minor bump in compression ratio from 11.5 to 11.8 as well.
Intake manifold - despite its apparent clean and efficient design with what looks like a well-shaped plenum and runners, the stock intake manifold is actually a major restriction to getting the best out of the motor. DDPR which is a race engineering company in the US which was founded from their design and build of a 2zz intake manifold that on a stock ECU with a 3" CAI saw 30whp at low RPM and 50whp gain at the lift transition of 6300 RPM – that’s pretty crazy for a bolt on!! With forced induction, the gains are even more impressive. Where do I sign up asap?!?!
DDPR have built some pretty swanky 2zz engines, check them out on facebook where there are some very nice pictures of a recently completed turbo build.
Now, I am aware the current motor I have makes 175whp which is very strong given it is rated 190 at the crank from factory; and is a pretty good all-round show compared with other stock, unopened 2zzge motors – one of the best I have seen with no mods except CAI and exhaust on stock ECU. Dyno plots here from these power runs are on some page here previous.
Not sure if my power goals are ambitious or reserved, but addressing the above weaknesses while addressing increased fuel flow with pump, rail, and injectors I am hoping for 220whp. On paper, this should be achievable. In addition to the reliability mods above, the plan for a bump in power and drivability will see:
- MWR Stage 3 cams
- Cosworth 0.38mm head gasket
- Head port
- Mechanical LSD install
Cams – with a higher flowing intake manifold and headwork for max airflow with stock sized valves, off the shelf cams should see decent power gains.
Stock 2zz cam specs:
Intake low-speed cam: 7.25mm lift, 228 deg duration
Intake high-speed cam: 11.2mm lift, 292 deg duration
Exhaust low-speed cam: 7.25mm lift, 228 deg duration
Exhaust high-speed cam: 10.0mm lift, 276 deg duration
MonkeyWrench Racing stage 3 cam specs:
Intake low-speed cam: 10.5mm lift, 276 deg duration
Intake high-speed cam: 12.3mm lift, 288 deg duration
Exhaust low-speed cam: 10.5mm lift, 272 deg duration
Exhaust high-speed cam: 12.1mm lift, 286 deg duration
The current changeover point from the low to high cam is the stock 6300rpm, but tuning the best possible power curve on both the low and high cams separately will show an intersect point as the best place to set the low to high cam changeover.
Headgasket – stock headgasket is 0.46mm. Using the Cosworth 0.38mm gasket will see a 0.2 bump in compression. Combined with the flat faced valves will net an increase from 11.5:1 to 12: 1 compression ratio. Will need to plastigauge (or bluetak-gauge
) the valve to piston clearance to make sure its clearances are all happy with another ~1mm of lift, ~1mm slimmer headgasket, and (hopefully much less than) ~1mm head skim on tidy up.
Headport – Head will be going off to an AW11 owning mate, Tim, at Pine Engineering
http://pine-engineering.co.nz/ for a “velocity port” and complete assembly.
Tim really knows his stuff, and gives the attention to detail and considered approach and has time for discussion about the engine/goals/build overall that a larger shop doesn’t necessarily do.
Keen to see how it turns out, and home much material he takes out of the ports.
It’s funny that a 2 minute conversation with Tim shows just how little I know about heads, airflow, valve and cam design, etc. A head port is definitely a job I am keen to leave to someone with the skills and experience.
LSD – hopefully all upgrades will see a decent net in whp. The wedge has been a bit of a YOLO car with its current power levels (You Only Leave One) and I have long thought about a Quaife, Kaaz or TRD helical LSD to upgrade. Could only be the 195 width tyres too though haha. It came up by way of a very generous gesture of another car nut that a TRD clutch-type LSD is now mine. Very low wear (effectively just been run in!) this will be a welcome upgrade. Can be setup 1.5 or 2 way.
Other supporting mods will be 440cc injectors, 190 lph fuel pump, enlarged billet fuel rail, new fuel filter and spark plugs, 3.5” intake piping, wideband oxy sensor.
Thoughts?
TL:DR == bunch of planned mods and parts for the head to hopefully put down 220whp in fine, naturally aspirated form.
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Good things take time, it's not far now.